51
FAULT FINDING
F
A
U
L
T
F
IN
D
IN
G
F
A
U
L
T
F
IN
D
IN
G
F
A
U
L
T
F
IN
D
IN
G
F
A
U
L
T
F
IN
D
IN
G
F
A
U
L
T
F
IN
D
IN
G
excel HE -
Installation and Servicing
Can the error be reset by
the reset procedure?
Does the pressure gauge
read > 1bar?
NO
YES
YES
NO
YES
Top up using filling loop
Fit and re-test
Check water pressure and
pump function
Is the PPS microswitch
fitted correctly?
(See Frame 65)
NO
When pump is running, is
there 0V across PPS
contacts?
Can you measure 5V dc on
PPS connector when pump
is stopped and 0V dc when
pump is running?
YES
Is PCB connector fitted
correctly?
NO
YES
Replace PCB
Fit and re-test
NO
Remove microswitch
assembly. Is the pressure
switch microswitch actuating
pin extending a min length of
10 mm
Check diaphragm.
Replace water set / pump?
NO
NO
82 ERROR CODE 3 - WPS / PPS ALARM
YES
YES
YES
NO
83 ERROR CODE 4 - APS / FAN ALARM
Does the fault clear
following the reset
procedure?
Is there movement from
the fan?
YES
YES
NO
YES
Run and observe operation
Is there 240V AC on fan
motor?
NO
Is PCB connector fitted
correctly?
NO
Is harness continuity OK?
YES
Replace fan
YES
Measure V DC across
APS NO/C contact is it 0V?
Is APS sensing pipe fitted
between fan and pressure
switch port marked L?
Is harness PCB connector
fitted correctly?
Stop the fan. Is the
voltage across the APS
contacts approx 30V DC?
YES
NO
Replace harness
Refit Hose
NO
Replace harness
Is harness continuity OK?
NO
Fit and retest
NO
Replace PCB